Vapor pressure bomb



July 25, 1933. H. SMITH VAPOR PRESSURE BOMB Filed May 2, 1929 WATER LEI/EL MA NOMETER uid or mixture thereof to ]o'e1';'ested.

The determination of the vapor 'pressure ofpure substances is e' comparatively simple" problem, but itis essential i'for "aceura eytha t the twe phases, liquid and vapor, 136111"(equl i 1 a composition of the liquid,beiiig'testedf I seine proportions in: whihii hei a e pr n 7 i gtorsecurlng extens ve-and intimate Contact Patented July 2 5 l933 II Assie n'oiz- TO TEXAS? I I "This"invention relates to an i nproved ep' .paratus for generating 'vapor rpressure W th- 1 in a closed bomb vvhich "iv-ill correspond closely to'the true vapor pressure of the 1111 ,,1ibriun'1,' the instant the ineasurement is However, in coniplex mixturess'uch'as ges'o line the components do not VL'POllZQ" in the in -the liquid phase; thusicausing a chang'e in the compo'sition of the residual liquid and consequentiye change in its vapor, pressure or ratherwhet would, have b6811 i-S VapQI" pressure before the changetook}piece Since the surface of, contact jbetiveenjthe liquid I and vapor is" the-{point at 'ivh ic h fali changes from liquidfto 'ga'se u ph ge [or-vice verse, take piac'eflt isreadily seen thetthe resulting equilibrium will bei governed'ena tirei fby the composition-and co ditionbf themore or less thin layers oif vepor a nd liq-E I uid which are in actual contact. It 1S5POISIS1E" ble to produce}euniiorin CODlPiOSltlOflWlilhlIi I eachfihas'e simple agitation but this alone A further oh I I I I I I I apparatus v t h Wh ch it closea'pp'ro 1niziti n 'sqbf'the true Vapor pressure of hq'uIdfor mix":

doesnotensurethat both phesesiwiil'be of the same COITIPOSltIOH, and th s is largely re- 7 sponsibie for' unsatisfactory a'ndzp erhztpsine aceu'rate results obtained fwith -previous 1'nethods end'zipparetus for measurlng-the" vapor jressure ef"complex mixtures; II

It 1s an ob ect of th s invention to, provide v zipperatus formeasuringthe 'vz i joi pressure I I of a liquid in which error due tO1ackofequ1- 401 l brium I 'of the phases is substantially 'eli m I I II I II cI. I I I Another object of the 'i I pressure of a complek'niixture?of'liquids ii coniposition of the, amp is materially reduced;

jest thereof is tin pr vide km made. In deaiingfivith pure substance this is not. a"difiicultr conditionrto establish-i; I I II I II II I I I I I I 1 tion of: both tlie iiqu d and the vap or 'tof -:;.b.6 g by'eon'tact between the meteria qiyt ej preferably by men-1830i an 'eieetriciinotior iof oiiand liquidphzts'esf I I I I {suitably"supported 'as indicated at 2 and -i adapted to contain a temperaturecontrolled =fluidfsueh as water for a' pur p'ose to presently; 1

ture thereof ineygbe produced/for the pu-r Jose ofinifleasuring thesam'e. r

"*iinother objec'tjof'theinvention is vide a novel apparatus for prodiicing age ho nogenize each phase;

"sen: another' objectis to rovi e ie-@8 betiveen the n'iaterial. in the two phases, and, to "agitate the material under-"test both phases, the agitation in the vapor "phase f tyvo'pheses. I I 1 "furtherobject of the invention is to" provide a closed 'vapor generating chzilnber I having means for" agitating the contained.

material, the agitating device being driven:

'ieducfion r i g h t rloce ed Side the am lh or: 'insidjthe chzunberend coi1iieeted'-tothe:agitator toy.v i

drive thejsenie, thuseliminztting a' shaft or other ChlYllig' conrie'ctlon passing through" ofieakagel;

the Ichaihb ei Welland"consequent liability )1 [Anothrobjectof thisfinventionis tofpro i vide apparatus ljy which the fvap or pressure of zilliquidor' mixturethereofezin bei nejas-i ured with speed andaccuracyend with little;

chance r errior from leakage.v 1 v The numeral" 11 indicates an 'olfien vessel app'e'ai- Secured-to thebottoin of-thefsves- A's'tiil further O je tthereofi s'to provide i an apparatus forthe'generation of a 'ivapor pressure to be I measured, in which the va er;

I Qtliei objects and advantages will hecoifie;

apparent in thedetailed description/Of the II v c I I apperetusembodying the invention wvhichf,

'ntion'i'sto pro-' i U vide-apparatusfiforQineasui ngfthe mp'or I v of {the japp'aiatiis for generating the vapor ijwhichi errorfdue" to lack tit-uniformity o ."Ypressurebf the' 1iquig1 t fbg i is formed at the upper portion of this sup'-' ",port and is adapted to contain mercury which may be supplied to it fromthe movable mercury bulb of a conventional mercury manometer in conjunction with which the apparatus herein disclosed is intended to be operated. The purpose of the mercury and a manner of supplying it to. cup 4 will be described hereinafter. The bottom of cup 4 may be provided with an extending tubular portion 5 of reduced diameter which passes through an opening in the bottom of vessel 1 and is intended to. be connected to the manometer or other pressure measuring device (not shown). Suitable packing 6 may be provided where tube 5 passes through the bottom of vessel 1 to prevent leakage of the water in the vessel through said opening. In the lower portion of cup 4 and upstanding around the junction of tube 5. with thebottom of the cup is an annular flange 7 forming a socket indicated by numeral 8. The interior of the socket may be screw threaded, and an annular shoulder 9 may be formed within the lower portion of the socket for the purpose of supporting a packing washer 10. A pin 11 passes throughtube 5 adjacent socket 8 for a purpose to hereinafter appear.

A closed fluid tight chamber 12 adapted to contain the liquid to be tested is formed of an upper tubular portion 13 and a lower portion 14, these being removably joined together in fluid tight engagement by means for pressing annular flanges 15 and 16 together. The lower end of chamber 12 is closed by the central portion of a supporting pedestal 17. a

1 The pedestal 17' is formed with a lower extension 18 of reduced diameter which is externally screw threaded and adapted to be screwed within socket 8 previously described. The center of the pedestal is provided with a bore 19 of stepped diameter, the lower and largest portion o1 which. is internally screw threaded for the reception of an externally threaded hollow plug20. The lower end of plug 20 is provided with a small aperture 21 and a valve seat 22. The internal diameter of hollow plug 20 isthe same as the diameter I of the next section of bore 19 andis in align-. ment therewith. \Vithin this section of the bore and the plug 20 is positioned a valve '23 having a stem 24. The valve is yieldis also provided at its lower end with a pin extension 26 of smaller diameter than aperture 21 which extension projects through said aperture and engages with pin 11 to force the valve open against the compression of its spring when the pedestal 17 isscrewed into position in socket 8. A number of pasceives the lower portion of a housing 30 of the stator 31 of the electric motor. The lower edge of the housing is pressed against a packing washer 32 which prevents passage of water into the housing between this edge and the disc 28. V f V The central portion of the pedestal 18 extends somewhat above the disc portion 28, and around this central portion an annular recess 33 is formed in the upper portion of the disc. tion 14 of the chamber 12 is received in this recess, and a packing 34 and packing nut 35 are provided to prevent leakage of the con tents of the chamber at this point. 7

The upper portion of housing 30 is provided with an annular shoulder 36 against The lower end of the lower porwhich flanges l5 and 16 previously referred a is reduced in diameter and is provided with a transparent tube 41 with graduated scale markings by means of which the volume ofv the vapor in the chamber may be observed through slot 42 in the wall of the chamber indicated in dotted lines. The inner surface of this reduced portion of chamber 12 ad- 7 j acent transparent tube 41 is internally screw threaded, and receives a valve assembly in-.

dicated generally by numeral 43. The valve assembly may consist of a hollow plug 44 and a valve stem 45 screwed into said plug and the lower end of the stem may be bevelled and form the valve proper- The valve assembly maybe screw-threadedly removable from and adjustable within the upper portion of chamber 12 in order-to permit replacement and use of various lengths of gage tubes 41.

y The valve may be provided."

with a seat at or near the upper end of the gage tube 41. lThe' valve is controlled by manipulation of knurlednut 46 on the upper end of the valve stem. The plug 43 maybe provided with a vent tube 47 which opens to atmosphere.

lVithin chamber 12there is provided a .1

mechanism for producing the desired agitationv of theliquld-and vapor contained therein. A vertically disposed tubey ll8; with I I small nozzle opening 49inits upper endhnd shaft 51 and propellers to vrotate, induc ing zt circuletion ofgthe llqu d in cha-inberll f With this. apparatus is "es follotvs. -Thevfar' sidewalls isilconcentricellysupported Within chzu'nber 12 103; support' 38., The tube l8 fis.

.lowerlportion' of chamber 12- :rdjacent the stator 31. The-shaft 56 of the :rotor, is roione or more inlet lopenings g50 in its -lovve-r so disposedjthetthje outlet opening 419 is adtube 41. A" vertical shaft Y 51' extends Within tube. 48,,suiteble spacing 'and-guidecollars 52. end 53 being provided for holding the shaft in its'proper position therein} A. nunr ber of propeller blades Marefixd tols'hzift 51 at suitable IlIItGIV2LlS. .Y t.

Therotor '55 of the. electric:'inotorfprei viously referredjto is positioned Within; the

tatably supported at: its lower end in'ball bearing support '57 in the central portionof pedestal r 1 1 'The shaft 51*is directly secured"ftoend driven bythe'-. shaft-56 of. the rotor. lhus, I When this fmechenism i'siin operation, rota tion otirotor=55 and its shaftbtl cause the upwardly through tube 48,:ind e 'fine spray of liquid is projected irom'no zzle' opening Y 49 into theiupper and'reducedportion of the" I I p p v p p i Y of hhB bOlHlO Wlll be substantially identical,"

chember12.- Yr p The" operation of nensuring the vapor pressure of a liquld'oranixture of l qu ds.

l2, stator31, and pedestal U, is removed" from the Waterbath by releasing thepedeskl slight pressure.

ventionztl manometer isfthen re iseduntil-j i the cup 4 is partially filled with mercury screwed in-plac e in socket 8. Valve'23, be ing-forced open by pin 11,]connect onis gestablished between theinterior of the bomb J expeditiously accomplished immerslng 50f tel from its socket 8. Y Whenthisis done; valve 23 au'tonmtically closes, 'Ylheboinb'is. then reduced to a low temperature "and may be filled preferably full with echilled liquid to be testedsucli as gasoline'throughlvalve opening 21.]"The chilledf liquid is forced ii'ito-thel bomb through yelve opening 45;

' pressure, The object 'Lof-using lowered tem' from a, source, preferably;v under afslight peratures is to prevent loss of vapor during the filling operation; The'chilllng maybe the bomb" in the usual ice and silt ini xtureh during thefilling' operation) During filling" I v q container adaptedT'to contain fluichun 1nducof the bomb'the' valve45lis opened, thus vent pipe-47. Vulv.e- 4 5 is then closed and thebomb is 'left, filled, preferably under a The movable mercury reservoirof aJc onthrough tube-5, fldhebomb is thenloxvered into the water bath (held'nt the desired ten n per-attire by any si utebjle means) end xend offthe' 1 bomb.

r 1 ooinb beginning ofthe test on ly-r'vi'pm space be filled with. I

brought equilibr'iuniivithout up rpreciable chyenge oi 'the proportions of the m Xture such is/ ould occurif a relatively afford an accurate-end direct Ineas'ureaof the and liquid sealed connection for'itrans Y and tlie inenfoineterl 011' "lowering theb'on'ib 7 into position. the mercury n: cup displaces any adheringiair'zlor wat=r from the lower Iflt'i's to be noted the-t the men is closed 7 only duringtheshort-interval of ti-me-vnecese P 'sery-for securing thefilled'boinb in place in theepparetustoreech it unii viii-Lees,- end uniforn1ityof'co1nwhich thelldesired ,inenometer- 'readingsmay v f be inadegs" It ll be'ireadily understood "the'tiif the conipletelyiillod vith liquid at the that will developed Wi ll. only the. t npors result ng 2 temperature nd, "a g1tation.

0111 increase .01":

andthe sanieis true of the va'por Fur.-

"therin'ore since the higher boiling-components and lower: boiling *ooniponents ere allj projected into the'vapor 'spacepequz'illy eech 10? t has. an equal. i

I v opportunity",- to vnpori'ze. I Thus each, component or, the mixture is large vapor space were used: this ap 'peratus, the common errors in previous vii;

por'jpressure tests are substantiallyeflim1- neted' and the manometer readings obtained true vapor pressure of the: inixture under 1. "In it [device oi the kind described, iii

tion driven device for homogenizing the components of fluids wlthin the container,

mi tting the pressure vvithin the container to a pressure measuring device.

2. In; a'device'for generating vapor presdriven device "for producing phase equili .jbrium of the contents ofthe container by inducing iLz-flOW of fluid fromsziid inlet through sa d (outlet and "means for trans 13-9 q 7 p I {-Due to the 0p- 0 erat on of the agitator in. drawing the liquid itroinbeneeth the, suri aceand projecting the her said tube havin an inlet and a reduced Jer )ortion constitutin a vaior chamber a p l r; 7

vertically disposed tube within said chamoutlet adjacent and inaxial alignment with and opening into said vapor chamber, an induction driven device for homogenizing the components of fluids within the container, and means for transmitting pressure developed within the chamber to a pressure indi- Gating device.

4. In a device of the kind described, a vertically disposed elongated chamber for con-' taining fluid, a longitudinally disposed tube withinthe chamber, a longitudinally disposed shaft provided with propeller blades Within said tube, and an induction driven device for rotating said shaft to induce a Q flow of fluid through said tube to produce phase equilibrium and means for transmittin oressure develo Jed within the chamber to a pressure mdicator.

5. In a device of the kinddescribed a vessel adapted to contain a temperature controlled fluid, a socket vvltliin the lower portion of said vessel, an upstanding flange about said socket forming a cup adapted to contain a fluid heavier than said first mentioned fluid, a closed bomb adapted to be, substantially immersed in said temperature controlled fluid and having a lower portion adapted to be nserted; in said socket, a valve in the lower portion of said bomb, and means in the socket for opening said-valve When.

said lower portion is inserted in said socket. 6. In a device of the kind described, a

V vessel adapted to contain a temperature controlled liquid, a vapor generatin hamber I I r b \J adapted to be lnserted in said vessel, an in- I duction motor, the rotor oi said motor being located Within said vapor generating chan'1- her, and a secondchamber containing the stator of said motor adjacent said first chamber when in assembled relation, said second chamber maintaining said; stator out of contact with said liquid.

ARRY LEIGHTON sMrrH. 

